Compounds containing an imide linkage

ABSTRACT

REACTION PRODUCTS OF POLYVARYLPOLYISOCYANTES AND AN ANHYDRIDE OF AN ALIPHATIC DICARBOXYLIC ACID, SAID ANHYDRIDE HAVING FROM 3-4 CARBON ATOMS, PHTHALIC ANHYDRIDE OR THE COMPLETELY HALOGENATED DERIVATIVES THEREOF OR CHLORENDIC ANHYDRIDE ARE DISCLOSED FOR USE IN RIGID FOAM COMPOSITIONS, SURFACE COATINGS AND THE LIKE.

United States Patent COMPOUNDS CONTAINING AN IlVIIDE LINKAGE John K.Allen, Batavia, 111., assignor to Standard Oil Company, Chicago, Ill.

No Drawing. Continuation-impart of abandoned application Ser. No.770,383, Oct. 24, 1968. This application Mar. 8, 1971, Ser. No. 122,100

' Int. Cl. C07d 27/52 US. Cl. 260-326 N 4 Claims ABSTRACT OF THEDISCLOSURE Reaction products of polyarylpolyisocyanates and an anhydrideof an aliphatic dicarboxylic acid, said anhydride having from 3-4 carbonatoms, phthalic anhydride or the completely halogenated derivativesthereof or chlorendic anhydride are disclosed for use in rigid foamcompositions, surface coatings and the like.

This application is a continuation-in-part application of Ser. No.770,383, filed Oct. 24, 1968 by the same inventor and currentlyabandoned.

BACKGROUND OF THE INVENTION This invention relates to novel compoundscontaining imide linkages which are formed by reactingpolyarylpolyisocyanates with selected carboxylic acid anhydrides.

Polyarylpolyisocyanates find use as constituents in polyurethane andpolyurethane-type foam compositions, both rigid and flexible. Trirnersof isocyanates, known as cyanurates, are recognized as distinctcompositions and can be further polymerized to produce foamedcompositions having utilities as fire resistant insulating materials.Iso cyanate-polyol repolymers are prepared by mildly reacting excessisocyanate with a polyol. Prepolymers may be combined with water toproduce foams or they may be reacted with extenders such as1,4-bntanediol, 3,3'-dichloro-4,4-diamino-diphenylmethane or thebis(beta-hydroxyethyl) ether of hydroquinone to form ela'stomers whichare frequently used to make cast articles. Isocyanates blocked byreacting with a phenol are used in industrial coatings such as wirecoatings.

I have now discovered a new class of compounds obtained by reactingpolyarylpolyisocyanates with an anhydride of an aliphatic dicarboxylicacid said anhydride having from 3-4 carbon atoms, phthalic anhydride orthe completely halogenated derivatives thereof or chloreudic anhydride,to form molecules containing both imido and isocyanato functionalgroups. These novel compounds may be substituted for isocyanates in manycommercial applications and result in products of equal or superiorproperties. Improvements in flame resistance and fire retardance areespecially noticeable. One of the most advantageous uses for my newcompounds is in the preparation of rigid cellular plastic compositionsto which improved flame resistance is generally imparted.

SUMMARY OF THE INVENTION The compositions of this invention comprise thereaction products of polyarylpolyisocyanates and an anhydride of analiphatic dicarboxylic acid, said anhydride having from 3-4 carbonatoms, phthalic anhydride or the completely halogenated derivativesthereof or chlorendic anhydride. Generally a polyarylpolyisocyanatehaving two or more isocyanate groups per molecule may be reacted withthe aforelisted anhydride of dicarboxylic acid. The reaction is atatmospheric pressure and at a temperature of between about ISO-300 C.Time-0f the reaction depends on the product viscosity desired.

3,823,158 Patented July 9, 1974 Polyarylpolyisocyanates suitable for thepreparation of the compounds of this invention are characterized byeither a structure having two benzene or methyl-, ethyl-, orpropyl-substituted benzene rings linked either directly or bridged by acarbonyl, sulfoxide, sulfone or ether group; or by a structure having2-10 benzene or methyl-, ethyl-, or propyl-substituted benzene ringslinked by alkylene groups of from l-3 carbon atoms, said benzene ringshaving one isocyanate functional group per ring, and an anhydride of analiphatic dicarboxylic acid, said anhydride having from 3-4 carbonatoms, phthalic acid anhydride or the completely halogenated derivativesthereof, or chlorendic anhydride at a temperature between 150 C. and 300C. and in a weight ratio of said polyarylpolyisocyanate to said acidanhydride of about 2:1 to 10:1. These polyarylpolyisocyanates contain atleast two aromatic rings, each ring being substituted by at least oneisocyanato group. The aromatic rings may be suitably intercon nected byone or more methylene, propylene, carbonyl, sulfoxide, sulfone or etherlinkages. Isocyanate-substituted biphenyls are also suitable. Thearomatic rings of any of the above compounds may be additionallysubstituted by ethyl, methyl or propyl groups. Specific examples ofsuitable polyarylpolyisocyanates for use with the invention include:polymethylene polyphenylisocyanates having from 2 to 10 benzene ringsand liquid mixtures at room temperature of polymethylenepolyphenylisocyanate with one or more of the followingpolyarylpolyisocyanates: 4,4 diphenylmethylene diisocyanate;diphenylmethylene 3,3'-diisocyanate; diphenyl diisocyanate;diphenylsulfone diisocyanate; diphenylsulfide diisocyanate;diphenylsulfoxide diisocyanate; and diphenylpropane diisocyanate.

. Polymethylene polyphenylisocyanates having an average benzene ringcontent of about 2.1 to 3.5 per molecule are particularly suitableisocyanates.

'carboxylic acids may be either aromatic or aliphatic and may containsubstituents such as halogen in addition to the carboxy functions.Suitable anhydrides include: phthalic anhydride, tetrachlorophthalicanhydride, tetrabromophthalic anhydride, maleic anhydride, malonicanhydride, succinic anhydride, chlorendic anhydride (Diels- Alderreaction product of hexachlorocyclopentadiene and maleic anhydride).Halogen containing anhydrides are generally preferred andtetrabromophthalic anhydride is especially preferred. These anhydrideswhen once reacted with an isocyanate group or a polyarylpolyisocyanateare incapable of further'reaction and thus extension of the system intopolymeric form.

The imide isocyanate-anhydride reaction products of this invention areprepared by combining the two components in a stirred vessel in thepresence of added heat until reaction occurs. It is advantageous toemploy N blanketing although the reaction may be conducted in openatmosphere. Ordinarily the reaction proceeds satisfactorily without acatalyst.

Reaction temperature may vary suitably between about 210-300 C.Preferred temperatures vary with the particular reactants but tendgenerally to be in the range 210-220" C. As can be seen in Table IV attemperatures below 210 C. or in the range C. C. no irnides are formed.

Product viscosity increases with increasing extent of reaction, and bycontinuing the reaction for a sufiicient length of time a solid productmay be produced. A given reaction is conducted for a length of timesuitable to achieve a product having the viscosity desired.

Viscosities of the products may also be controlled by the ratios ofreactants employed.

For liquid products of medium viscosities which are principally used inrigid foam formulations, it is frequently preferred to react about 2weight parts of the isocyanate with 1 Weight part of the anhydride andsubsequently to dilute the product to th e desired viscosity withadditional isocyanate. The two-step procedure produces a product havinga lower viscosity than a one-step product having the same final weightratio of isocyanate to anhydride.

Further to illustrate my invention the following examples are includedwhich are not intended to be limitative.

EXAMPLE I Equivalent Isoeyanate Functionality weight Polyfunctionalcarboxylic acid anhydrides employed in the adducts are identified by thefollowing symbols:

TABLE 11 Reaction T T addutet Stotrage P emp. ime viscosi y ime recip-Adduct number 0.) (his) (cp.) (days) itation 205 8 440 19 L 205 10 50519 L 205 12 1,600 15 N 205 14 5,200 15 S 210 5 450 20 M 210 6 470 20 M210 7 1,075 21 N 210 10 2,150 21 S 215 5 1,200 14 N 215 7 050 26 S 21510 14,400 26 S 220 3 570 28 M 220 4 1,450 27 S 220 5 4, 250 27 S 220 611, 000 14 S N 0TE.L=Large; M=Medium; S=Small; N=None.

EXAMPLE III Six hundred pounds of NCO-10 isocyanate, identified inExample I was charged to a 200 gallon stainless steel reactor fittedwith a 44 rpm. stirrer and maintained under a nitrogen blanket flowingat cubic feet per hour. Three hundred pounds of tetrabromophthalicanhydride were added and the temperature raised to 410 F. The reactorwas maintained under these conditions for 7 hours after which the hotreaction mixture was diluted with 900 pounds of cold (ambienttemperature) NCO-20, a polyphenylpolyisocyanate having a functionalityof 2.6 and an equivalent weight of 133.

The diluted reaction mixture was cooled to 200 F. and discharged intostorage. No precipitation occurred during cooling of the product toroomtemperature. Viscosity at 74 F. was 8,000 cp. Infrared analysisindicated that approximately 50% of the anhydride groups had reacted toform imide.

EXAMPLE IV Fire-resistant cellular plastic foams were prepared withSymbol: Anhydride name B PAN b h h li h d id the reaction product ofExample III. These foams were C1 1 AN Tgtl'achlorophthalic h d id ratedin ASTM test B 84-61 for Surface Burning Charac- TMA Phthalic anhydride.ics f Building Materials. The foams received 3 AMA Trimelliticanhydride. 45 fl e spread rating satisfying current comm i ClANChlorendic anhydride. t da ds for approved building materials.

TABLE I h d d t Hfiattu T h 1d Addiict scosity dduct Isoe anateAnhydride an y ri e ime min. ime e V1 umber type type Weight ratio to500 F. at 500 1*. (cp. 75 F.)

12- MR BriPAN 2/1 18 0minutes.- Very viscous.

20. MR. BriPAN 5/1 17.6 .....(10

26. Papi--- BriPAN 5/1 Very viseous.

27-.. 3901 BriPAN 5/1 Some solid separated.

28.-. N00 BI'4PAN 5/1 Very viscous.

29 7418 BriPAN 5/1 980,000

30... Isonate 500.. riPAN 5/1 ..d Very viscous.

31. BnPAN 5/1 do Some solid separated.

25. PAN 20/1 10. d0 650.

55. CliPAN 2/1 14.7 l5minutes- Solid.

58. C14PAN 5/1 19.0 0 Do.

59. ChPAN 5/1 30 m1nutes.-.. 950.

48- P BriPAN 4/1 10. 5 5 minutes- 48,500.

37.-. MF BriPAN 5/1 20.4 15 minutes 400.

H-8.. NCO-10..-- CIAN 2/1 1 hour Solid precipitated.

H-10.-. NCO-10---. ClAN 2/1 2 hours 2 18,900.

RW 47 NCO-10...- CLAN 5/1 4 hours 5 780.

1 Heat-up time to 410 F. was 38 min.

1 At 410 F.; reaction was carried out in a 1 l. flask. 3 Heat-up time to410 F. was 35 Inn.

Heat-up time to 392 F. was 30 min.

5 At 392 F.; reaction was carried out in a 1 1. flask.

EXAMPLE ii reaction product.

The foams were prepared by combining, in the proportions indicated, thecomponents given in Table III below. Symbols used in Table III have thefollowing meanings:

51B: The isocyanate-anhydride reaction product of Example III. DC-: Asiloxane glycol block copolymer surfactant.

DBTDA: Dibutyltin dia cetate.

Formulation (parts by weight) Evaluation Sur- Flame Polyol 'IMA iactantCFCI Catalyst Additive Cure spread 3.3 1. 67 33.4 1.67 12.5 150 F./1.5hour 25 Preparation conditions Adduct viscosity Tempera- Time, Tempera-Value ture (F.) 5. ture (F.) (cp.)

210 74 5, 800 Considerable reaction to give cyclic imide.

120 72 1 548 Solid portionmainly unreacted tetrabromo phthalicanhydride; liquid portion-mainly unreaeted isocyanate.

74 Very little, if any, amide or imide formation g 30, 2 10) N103 imide;very small amount of amide. 2 0.

TABLE 111 Chemical types Sur- Addi- Isoeyanate Polyol factant Catalysttive Isocyanate }Do-195 DBTDA 0-22-11 D 0-195 DBTDA C22R PEP 450 }DO195DBTDA C22R TAB LE IV Chemical components Final isocy- Anhydride Reaetantisocyante Diluent isocyanate anate/anhydride weight Weight (g.) TypeWeight (g.) Type Weight (g.) ratio 750 NCO-10 1, 500 NCO-20 2, 250 5/1750 NCO-40 1, 500 NCO-20 2, 250 5/1 750 NOC-IO 1, 500 NCO-20 2, 250 200NCO- 2,000 400 NCO-10 2,000 1 The product consisted of solid and liquidportions; the viscosity of the liquid portion was determined.

132/A TMA ISM/A"-.. 'IMA 135/A..--- TMA Number 51A-1.5 51B 436B-1.5--.-518 463-15......... 51B

Adduct reference number C22-R: A chlorine-containing organophosphorouscompound used as a flame-retardant having the following structure:

ClCHzCHz CH3 0 CHzCHzCl 10 TMA: Trimellitic anhydride.

S691: A reaction product of 5 parts of a propoxylated sucrose aminepolyol (E.W. 94), 5 parts of poly(ethyleneglycol) (E.W. 200) and 4 partschlorendic anhydride.

2406A: A propoxylated hexitol polyol manufactured by Atlas and having anequivalent weight of 88, a functionality of 6 and a hydroxyl number of640.

S667: A reaction product of 2 parts of a propoxylated pentaerythritolpolyol (E.W. 100) and 1 part of tetrabromophthalic anhydride.

PEP-450: A propoxylated pentaerythritol polyol manufactured by Wyandotteand having an equivalent weight of 100, a functionality of 4 and anhydroxyl number of 561.

I claim:

1. The reaction products prepared by reacting a mixture consistingessentially of a polyarylpolyisocyanate consisting of 2-10 benzene ormethyl-, ethyl-, or propylsubstituted benzene rings linked by methylenegroups,

said benzene rings having one isocyanate functional group per ring, anda compound selected from the group consisting of phthalic anhydride,tetrachlorophthalic anhydride, tetrabromophthalic anhydride, andchlorendic anhydride at a temperature between 150 C. and 300 C. and in aWeight ratio of said polyarylpolyisocyanate to said anhydride of about2:1 to 10:1.

2. The compound of Claim 1 wherein the reaction temperature is betweenabout 200 C. and about 220 C. and the weight ratio of polyisocyanate toacid anhydride is between 2:1 and 10:1.

3. The compound of Claim 1 wherein the polyarylpolyisocyanate is amixture of materials characterized by having 2-10 benzene rings linkedby methylene groups, said benzene rings having one isocyanate functionalgroup per ring, and the acid anhydride is perbromophthalic acidanhydride.

4. A process for preparing a polyarylpolyisocyanatedicarboxylicacid-anhydride reaction product having a viscosity suitable for use inpreparation of a rigid, cellular,

plastic foam comprising:

(1) reacting at a temperature from about 150 C. to 300 0, one part byWeight of the dicarboxylic acid anhydride of Claim 1 with about 1 toabout 2 parts by weight of the polyarylpolyisocyanate of Claim 1;

and

(2) diluting the hot reaction mixture with sufficientpolyarylpolyisocyanate of Claim 1 to achieve a weight ratio ofpolyarylpolyisocyanate to dicarboxylic acid anhydride of from about 2:1to about References Cited UNITED STATES PATENTS 3,314,923 4/1967 Mullera a1. 260-78 3,445,477 5/1969 Muller er al 260-326 FOREIGN PATENTS1,058,236 2/1967 Great Britain 260-326 a E JOSEPH A. NARCAVAGE, PrimaryExaminer D- U.S. c1. X.R. U2 2524.1; 260-3265 FM '-CERTIFICATE OFCORRECTI'ON,

Patent No; 3,823,158 Dated July 9, 197

Inventor(s) John K. Allen It is certified that error appears in theabove-identified paten't and that said Letters Patent are herebycorrected 'as shown below:

Column 3, line #3, under "Symboh" "TMA" should be "PAN- 3 M under"Sumbolz" "AMA" should be --TMA-- Table In; List oolumn, 361 down;has-1.5" should be --m+6B-1. Table IV, 3&- columh, sub-heading "Ractantisocyante" should be --Reactant isocyanate'". under "Type" in "Reactantisocyanate" column, 3d down,

' "moo-1o" should be q-NCO-lO-i.

' Signed arid sealed this 15th day of October 1974.

(SEAL) 4 I 4 Attest: l

MCCOY M. .GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner. ofPatents 03191012 e Q-CERTIFICATE OF CORRECTION.

Patent No. 3,823,158 Dated July 9, 197 i- Inventor(s) John K. Allen Itis certified that error appears in the above-identified pate and thatsaid Letters Patent are hereby corrected es shown below:

Col1 1 mn 3, line +3, under "Symboh" "TMA" should be --PAN-- 3 v M under"Sumbolz" "AMA" should be --TMA--.

Table 111:; 1st oolumn, 3a down; mas-1.5" should be M+6B-1.5--.'

Table IV, 3d column, sub-heading "Reactant isocyante" should be n--Heact ant 1socyanate'--. V

under "Type" in "Reactant iaocyanate" column, 3d down,

- "KOO-10' should be "NCO-10". I

' Signed and sealed this 15th day of. October 1974. I

(SEAL) i Attest: V e

MCCOY M. ,GIBSON JR. I 7 c. MARSHALL DANN Attesting OfficerCommissioner. of Patents

